Sabina vulgaris Ant. is a native evergreen conifer that is endemic to semiarid regions in northern China. It has prostrate stems with roots and makes patchy stands with stems spreading radially on the ground. It has previously reported that those patches cover effectively to prevent a litter and organic matter removal by seasonal northwesterly wind in spring, and eventually their patch makes “island of fertility”. To clarify the nitrogen utilization and its transition with life cycle of S. vulgaris, field investigations were conducted in the Mu-Us desert, Inner Mongolia in 2007-2009. Four patches with different stand ages were selected.
Results/Conclusions
d15N of leaves of stands increased with age, and the change of leaf d15N were corresponding to those of soil organic matters in each stand, suggesting tight nitrogen recycling exists between soils and trees, and heavier nitrogen has accumulated in the soil profiles. Root distribution survey suggested that some stands have been buried by drifting sand dunes several times during the transition of life stages. This implies that the S. vulgaris stands have always been adjoining with drifting dune, although it has generally been explained that the drifting sand dunes was generated by severe removals of the native stands of S. vulgaris.